1. Technical Field
The present invention relates to an ink jet printer and a printing method.
2. Related Art
In the related art, a printing method using an ink jet printer is performed by causing small ink droplets to be scattered and then attached onto a medium such as paper. Recently, according to innovative advancement in ink jet printing technology, printing has been performed on a medium formed of fabric such as silk, polyester, and cotton which have high absorbency of ink, and a plastic-based medium which does not absorb ink by the ink jet printer.
When performing the printing on the plastic-based medium by the ink jet printer, a technique of improving a surface of the medium which is modified by being irradiated with the plasma, thus increasing the affinity between the medium and ink (for example, refer to JP-A-2009-279796, JP-A-2012-179748, and JP-A-2012-179747) has been known.
JP-A-2009-279796, and JP-A-2012-179748 disclose a plasma irradiation mechanism which is provided separately from a carriage. The plasma irradiation mechanism disclosed in JP-A-2009-279796 and JP-A-2012-179748 is provided with a pair of electrodes which interposes a medium therebetween and performs a surface treatment by causing the plasma generated between these electrodes to come in contact with the medium.
JP-A-2012-179747 discloses a plasma irradiation mechanism which is a plasma irradiation mechanism mounted in a carriage and is disposed so as to be along the direction orthogonal to the travelling direction of the carriage (for example, refer to a paragraph [0012]). The plasma irradiation mechanism disclosed in JP-A-2012-179747 performs the surface treatment by causing the plasma, which is generated between a pair of electrodes (4 and 5) disposed on the same side with respect to a medium, to come in contact with the medium (for example, refer to paragraph [0015]).
As described above, in JP-A-2009-279796, JP-A-2012-179748, and JP-A-2012-179747, the surface treatment is performed through a so called direct method of causing a discharge portion to directly come in contact with a medium. The direct method is a method of performing the surface treatment on a target to be processed by generating the plasma in a state where the target to be processed is disposed between electrodes.
However, in the surface treatment performed through the direct method, since a discharge portion directly comes in contact with the medium, the medium is likely to be damaged or discolored.